The harmful effects of oil spills in marine and fresh water environments are well known. Typically, such spills take the form of relatively thin "slicks" oil floating on the surface of the water. A major challenge in most clean-up operations is collecting these slicks and somehow concentrating them so that the material can be removed from the body of water. One device which has been used in the past for collection of oil spills is a simple U-shaped boom which is towed by two vessels. Oil is captured between the open ends of the boom and collected at the closed end of the "U". A variation has been to add a weir skimmer at the closed end of the boom; as is known to those skilled in the art, a weir skimmer is a collection device having a shallow barrier over which the slick passes for concentration in a collection area.
Traditional U-shaped booms have proven modestly successful, but only if the weather and other conditions are near ideal. Surface "chop" or other wave action tends to become greatly magnified at the closed end of the boom, with the result that spillage or damage may occur under even relatively mild conditions. Furthermore, the apparent velocity of the collected material becomes greatly accelerated near the closed end, making the liquid difficult to control and contain. These complications are particularly detrimental to the operation of a weir skimmer: simply put, the increased chop and velocity tend to push oil and water over the weir indiscriminately, rendering it incapable of collecting and concentrating the oil slick as intended. Also the weir skimmer can easily be damaged by foreign objects (e.g., garbage and floating wood), especially as these may be propelled by the additional turbulence which occurs at the closed end of the boom. However, it should be noted that a simple U-shaped boom lacking a weir skimmer provides only limited concentration and containment of an oil slick, making it very difficult to remove this material from the surface of the water.
Accordingly, there exists a need for an effective system for capturing and collecting oil spills, even under relatively adverse sea conditions. The need also exists for such a device which will permit relatively higher speeds of operation by the towing craft and which can be operated in the presence of floating debris without fear of damage. Still further, there is a need for such a device which provides for increased concentration and containment of the collected oil, so as to facilitate its removal from the body of water.